Bonsoir,
A = (2/3 + 9) / (- 9/2 + 9)
A = [2/3 + (9 x 3) / (1 x 3)] : [- 9/2 + (9 x 2) / (1 x 2)]
A = (2/3 + 27/3) : (- 9/2 + 18/2)
A = 29/3 : 9/2
A = 29/3 x 2/9
A = 58/27
B = 9/7 : (- 1/10 - - 1/7)
B = 9/7 : [(- 1 x 7) / (10 x 7) + (1 x 10) / (7 x 10)]
B = 9/7 : (- 7/70 + 10/70)
B = 9/7 : 1/70
B = 9/7 x 70
B = 630/7
B = (7 x 90) / (7 x 1)
B = 90.
C = - 12/11 + 20/11 : 16/11
C = - 12/11 + 20/11 x 11/16
C = (- 12 x 16) / (11 x 16) + 220/176
C = - 192/176 + 220/176
C = 28/176
C = (4 x 7) / (4 x 44)
C = 7/44.
